JPS6267347A - Vibro-isolating device - Google Patents

Abstract

PURPOSE:To obtain a stable characteristic of damping by a device simplifying its construction, by providing a lead or lead alloy made stopper, which restricts the relative displacement between both a main unit structure and a supporting structure, to be interposed between these structures. CONSTITUTION:A lead stopper 1, being formed into a protrusive type, provides holes for bolts in a flange part. Said lead stopper 1, providing the flange part 4 of a bottom shape steel or the like provided in a structure 3 constituting an iron lower while providing a steel plate 6 for preventing lead from sinking due to locally tightening force of nuts 5, is fixed so as to be put between the flange part 4 and the steel plate 6. While a pair of rigid overhangs 9 of H-steel or the like are provided in the side of a cylinder body 7 in such a manner that the lead stopper 1 is put between the overhangs in a reinforcing ring 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a vibration isolator that can be used in structures whose main body structure is supported from the surroundings, such as tower-supported chimneys and hanging boilers.

(Prior Art) Conventionally, rubber, wire springs, oil dampers, viscous dampers, etc. have been installed between the main structure and the support structure as damping additions to reduce vibration.

When targeting normal-sized structures, this type of vibration isolator can withstand loads of several tens of tons under normal conditions, but in the event of a major earthquake, the load stops transmitting relatively quickly. In addition, it is necessary to absorb a large amount of energy through a relatively large deformation of several 10c111, and to have stable characteristics with little deterioration even when subjected to repeated forces. Also, from a cost perspective, the key points are that the mechanism is simple and easy to install, and that it does not require much maintenance. Furthermore, when rubber is used as a damping additive,
The characteristics were unclear, and the problem was that the characteristics changed over time.

On the other hand, wire springs had insufficient energy absorption effects and were less effective in reducing vibrations during large earthquakes. In addition, although it is possible to manufacture oil dampers and viscous dampers that are satisfactory in terms of performance, they must be used in conjunction with elastic springs that bear the restoring force, making the mechanism complicated.
Competing with structures becomes a problem. Furthermore, in the case of oil dampers, since flammable oil is used, there are safety problems such as oil leakage and fire, and frequent maintenance is required. In addition, viscous dampers cannot be expected to have a stable damping effect because the characteristics of the viscous material used are greatly affected by the ambient temperature.

(Problems to be Solved by the Invention) The present invention seeks to solve problems in conventional vibration isolators, such as unclear characteristics and complicated mechanisms, safety issues, etc. .

(Means for Solving the Problems) For this reason, the present invention provides a stopper made of lead or lead alloy that is interposed between the main body structure and the structure that supports it so as to restrain the relative displacement between the two. The purpose of this is to provide a means for solving problems.

(Function) Lead has clear characteristics and yields at about half the load of iron or steel, so it can withstand loads of several tens of tons, but the transmission of force between the main structure and the supporting structure becomes difficult. This is because it deforms faster than iron or steel for the same dimensions, absorbs deformation of several tens of centimeters in the event of a major earthquake, and has less deterioration due to repetition, resulting in stable characteristics.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings. Fig. 1 shows an example in which a lead stopper is attached to a tower-supported chimney according to an embodiment of the present invention. In the figure, the lead stopper 1 in this example has a convex shape as shown in FIG. 3, and a hole 2 for a pole 1 is provided in the flange portion. This lead stopper 1 is sandwiched between a flange portion 4 such as a lower mold steel provided on a structure 3 that constitutes a steel tower, and a steel plate 6 provided to prevent the lead from collapsing due to local tightening force of bolts and nuts 5. It is fixed as follows. - There is a reinforcing ring (body structure'$
A pair of four-pronged protrusions 9 made of H-shaped steel or the like are provided with a lead stopper l sandwiched between the protrusions 9 and 8.

FIG. 2 shows an example in which a lead stopper is attached to a hanging boiler according to another embodiment. In this case as well, as in FIG. 1, the lead stopper 1 is fixed with bolts and nuts 5 so as to be sandwiched between the member 10 constituting the boiler steel frame and the steel plate 6. On the other hand, on the boiler main body 11 side, as in FIG. 1, two rigid overhangs 9 are provided on the backstay 12 so as to sandwich the lead stopper 1 therebetween. Note that the shape and fixing method of the lead stopper are not limited to those of this embodiment as long as they can be firmly fixed.

As described above, if a disturbance such as an earthquake or wind is applied with the lead stopper installed, the main structure (in this example, the cylinder body, the boiler body) and the support structure (in this example, the steel tower, the boiler steel frame) will be damaged.
Because they have different rigidity and weight, relative deformation occurs between the two as they try to move in different ways, and the lead stopper
A shear force is applied to resist this relative deformation.

The relationship between this shearing force Q and relative deformation δ is shown in the fourth
It is a diagram. In addition, point A in the figure is the lead stopper! 13 [
r At the yield position, it is about half the size of iron or steel and can withstand a certain amount of shearing force, but the transmission of force between the two reaches a plateau at a relatively early point. During a major earthquake, the transmission of force has reached a plateau and only deformation progresses from A to B.
point, and then move from B to C by swinging back the structure.
Move to point D and absorb energy equivalent to the area surrounded. Each time this loop is repeated, a large amount of energy is absorbed and vibrations are reduced.

Lead has excellent deformation performance and fatigue properties even when such phenomena are repeated, and its mechanical properties constantly try to restore itself even after yielding, so it has a strong damping effect (and stable properties). Obtainable.

(Effects of the Invention) As explained in detail above, the present invention is constructed so that when lead is used, it yields at about half the load of iron or steel, so
It can withstand a load of approximately 20 tons with a cross-sectional area of m x 15 cm, but if it receives an excessive load, it will quickly become plastic, and further loads will not be transmitted between the main structure and the supporting structure, causing damage to other parts. It is possible to prevent the spread of damage to. In addition, lead has excellent deformation and fatigue properties, so it has a large damping effect and stable properties against repeated forces such as those caused by large earthquakes. Second, it can be designed into a relatively simple shape and can be easily assembled with structures.

[Brief explanation of drawings]

FIG. 1 shows a first embodiment of the vibration isolating device of the present invention' (
FIG. 2 is a plan view of the lead stopper installed on a tower-supported chimney, FIG. 2 is a plan view of the lead stopper installed on a suspended boiler as a second embodiment of the present invention, and FIG. The perspective view and FIG. 4 are explanatory diagrams of the shearing force applied to the lead steel and the relative deformation. Explanation of the main parts of the diagram 1 - Lead stopper 3 - Structure 5 - Bolts and nuts 8 - Main structure patent Applicant Mitsubishi Heavy Industries, Ltd. Figure 1 Figure 3 Figure 4 0゛

Claims (1)

[Claims] A vibration isolator characterized in that a stopper made of lead or lead alloy is interposed between a main body structure and a structure supporting the same so as to restrain relative displacement between the two.